HK Army makes high-end barrel kits for your favorite paintball gun. All of their barrels are made with the highest grade aluminum and are precision-honed, giving you a consistent, smooth interior finish for maximum accuracy. Make sure to match your barrel insert to the paintballs you are shooting. The paintball should not be able to roll out the barrel, or be so tight that you cannot force it out by blowing into the barrel. Using a barrel kit with a variety of insert sizes helps you get the best paintball-to-bore match.